Researchers have long been puzzled by large societies in which strangers routinely engage in voluntary acts of kindness, respect and mutual benefit even though there is often an individual cost involved.
While evolutionary forces associated with kinship and reciprocity canexplain such cooperative behavior among other primates, these forcesdo not easily explain similar behavior in large, unrelated groups,like those that most humans live in.
A new study co-authored by University of California, Davis, anthropologist Richard McElreathand published today in Science magazine suggests that the cooperativenature of each society is at least partly dependent upon historicalforces - such as religious beliefs and the growth of markettransactions.
The study also found the extent to which a society uses punishment toenforce norms increases and decreases with the number of people inthe society.
"It is likely that small and large communities regulate cooperation -mutual defense, conservation, etc. - in different ways, becausedifferent mechanisms of monitoring and enforcement of norms workbetter at different scales of society," explained McElreath, anassociate professor of anthropology at UC Davis.
"A small town in Kansas, for example, can likely rely upon reputationand the fact that everyone knows everyone else, while the residentsof New York City need some mechanism, like punishment, that can workin the absence of reliable reputations," he said.
McElreath was one of 14 researchers on three different continents whoparticipated in the project detailed in the paper, "Markets,Religion, Community Size, and the Evolution of Fairness andPunishment." The first author is Joseph Henrich, an associateprofessor in the departments of Psychology and Economics at theUniversity of British Columbia.
The researchers probed why communities often cooperate in diverseways, from mutual defense to conservation. People engage in suchmutually beneficial acts even though they may be individually costly.
Using behavioral experiments administered across 15 diversepopulations, the study sought to measure the influence of threedifferent mechanisms - punishment, market integration and religiousbeliefs - that might maintain cooperation within societies. Marketintegration is the extent to which individuals use anonymous,rule-governed transactions to buy and sell goods.
The researchers found that overt punishment, religious beliefs thatcan act as a form of psychological punishment and market integrationeach were correlated with fairness in the experiments.
Source: University of California - Davis